Model Comparison

Gemini 3.5 Flash-Lite vs GPT-5.3 CodexWhich is better in 2026?

Both models are evenly matched across the benchmarks. Gemini 3.5 Flash-Lite is 5.7x cheaper per token.

Verdict: Gemini 3.5 Flash-Lite vs GPT-5.3 Codex — which is better?

Gemini 3.5 Flash-Lite (by Google) and GPT-5.3 Codex (by OpenAI) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.

Gemini 3.5 Flash-Lite outperforms in 1 benchmarks (OSWorld-Verified), while GPT-5.3 Codex is better at 1 benchmark (SWE-Bench Pro). Both models are evenly matched across the benchmarks.

On price, Gemini 3.5 Flash-Lite is roughly 5.7x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Gemini 3.5 Flash-Lite also accepts a larger context window (1,048,576 input tokens), making it the stronger choice for long documents and large codebases.

Choose Gemini 3.5 Flash-Lite if…

  • cost matters — it's about 5.7x cheaper per token
  • you process long inputs — it offers a 1,048,576 token context window
  • you want the most recent training data — it shipped Jul 2026

Choose GPT-5.3 Codex if…

  • you want predictable pricing at $1.75/M input and $14.00/M output

Performance Benchmarks

Comparative analysis across standard metrics

2 benchmarks

Gemini 3.5 Flash-Lite outperforms in 1 benchmarks (OSWorld-Verified), while GPT-5.3 Codex is better at 1 benchmark (SWE-Bench Pro).

Both models are evenly matched across the benchmarks.

Mon Jul 27 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Gemini 3.5 Flash-Lite costs less

For input processing, Gemini 3.5 Flash-Lite ($0.30/1M tokens) is 5.8x cheaper than GPT-5.3 Codex ($1.75/1M tokens).

For output processing, Gemini 3.5 Flash-Lite ($2.50/1M tokens) is 5.6x cheaper than GPT-5.3 Codex ($14.00/1M tokens).

In conclusion, GPT-5.3 Codex is more expensive than Gemini 3.5 Flash-Lite.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Mon Jul 27 2026 • llm-stats.com
Google
Gemini 3.5 Flash-Lite
Input tokens$0.30
Output tokens$2.50
Best providerGoogle
OpenAI
GPT-5.3 Codex
Input tokens$1.75
Output tokens$14.00
Best providerOpenAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Gemini 3.5 Flash-Lite accepts 1,048,576 input tokens compared to GPT-5.3 Codex's 400,000 tokens. GPT-5.3 Codex can generate longer responses up to 128,000 tokens, while Gemini 3.5 Flash-Lite is limited to 65,536 tokens.

Google
Gemini 3.5 Flash-Lite
Input1,048,576 tokens
Output65,536 tokens
OpenAI
GPT-5.3 Codex
Input400,000 tokens
Output128,000 tokens
Mon Jul 27 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Gemini 3.5 Flash-Lite and GPT-5.3 Codex support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

Gemini 3.5 Flash-Lite

Text
Images
Audio
Video

GPT-5.3 Codex

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Gemini 3.5 Flash-Lite

Proprietary

Closed source

GPT-5.3 Codex

Proprietary

Closed source

Release Timeline

When each model was launched

Gemini 3.5 Flash-Lite was released on 2026-07-21, while GPT-5.3 Codex was released on 2026-02-05.

Gemini 3.5 Flash-Lite is 6 months newer than GPT-5.3 Codex.

Gemini 3.5 Flash-Lite

Jul 21, 2026

6 days ago

5mo newer
GPT-5.3 Codex

Feb 5, 2026

5 months ago

Knowledge Cutoff

When training data ends

Gemini 3.5 Flash-Lite has a documented knowledge cutoff of 2026-03-31, while GPT-5.3 Codex's cutoff date is not specified.

We can confirm Gemini 3.5 Flash-Lite's training data extends to 2026-03-31, but cannot make a direct comparison without GPT-5.3 Codex's cutoff date.

Gemini 3.5 Flash-Lite

Mar 2026

GPT-5.3 Codex

—

Provider Availability

Gemini 3.5 Flash-Lite is available from Google. GPT-5.3 Codex is available from OpenAI.

Gemini 3.5 Flash-Lite

google logo
Google
Input Price:Input: $0.30/1MOutput Price:Output: $2.50/1M

GPT-5.3 Codex

openai logo
OpenAI
Input Price:Input: $1.75/1MOutput Price:Output: $14.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

Google
Larger context window (1,048,576 tokens)
Less expensive input tokens
Less expensive output tokens
Higher OSWorld-Verified score (74.0% vs 64.7%)
OpenAI
Higher SWE-Bench Pro score (56.8% vs 54.2%)

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Gemini 3.5 Flash-Lite and GPT-5.3 Codex side-by-side, then vote on the output you prefer.

Gemini 3.5 Flash-Lite
✓ Preferred
GPT-5.3 Codex
Open in Playground
AI Model Comparison Table
Feature
Google
Gemini 3.5 Flash-Lite
OpenAI
GPT-5.3 Codex

FAQ

Common questions about Gemini 3.5 Flash-Lite vs GPT-5.3 Codex.

Which is better, Gemini 3.5 Flash-Lite or GPT-5.3 Codex?

Both models are evenly matched across the benchmarks. Gemini 3.5 Flash-Lite is made by Google and GPT-5.3 Codex is made by OpenAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Gemini 3.5 Flash-Lite compare to GPT-5.3 Codex in benchmarks?

Gemini 3.5 Flash-Lite scores CharXiv-R: 76.5%, OSWorld-Verified: 74.0%, SWE-Bench Pro: 54.2%, Terminal-Bench 2.1: 54.0%, MLE-Bench: 39.2%. GPT-5.3 Codex scores SWE-Lancer (IC-Diamond subset): 81.4%, Cybersecurity CTFs: 77.6%, Terminal-Bench 2.0: 77.3%, LiveBench: 72.8%, OSWorld-Verified: 64.7%.

Is Gemini 3.5 Flash-Lite cheaper than GPT-5.3 Codex?

Gemini 3.5 Flash-Lite is 5.8x cheaper for input tokens. Gemini 3.5 Flash-Lite costs $0.30/M input and $2.50/M output via google. GPT-5.3 Codex costs $1.75/M input and $14.00/M output via openai.

What are the context window sizes for Gemini 3.5 Flash-Lite and GPT-5.3 Codex?

Gemini 3.5 Flash-Lite supports 1.0M tokens and GPT-5.3 Codex supports 400K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Gemini 3.5 Flash-Lite and GPT-5.3 Codex?

Key differences include context window (1.0M vs 400K), input pricing ($0.30 vs $1.75/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Gemini 3.5 Flash-Lite and GPT-5.3 Codex?

Gemini 3.5 Flash-Lite is developed by Google and GPT-5.3 Codex is developed by OpenAI.

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